There are known granulating devices of the general type above referred to in which granulation is effected by cooling the outlet side of the nozzle and providing cutting knives sweeping over the cooled nozzle side. Nozzles used for this type of granulation have several bores extending in axial alignment with the flow of the material to be granulated. There is also provided between the inlet and the outlet areas of the nozzles bores a radially extended insulation layer. The nozzle bores also have in their lengthwise direction a heat insulation in the form of a coherent insulation material of low heat conductivity filling a gap extending about at least several nozzle bores on the inlet side thereof. This filled gap extends radially within the range of the outlet side of the nozzle bores. Granulating devices of this type are shown in applicant's prior U.S. Pat. No. 3,867,082, issued Feb. 18, 1975.